From f87bbab22cf5a81dd314c7811867edc5c69025d2 Mon Sep 17 00:00:00 2001
From: Slobodan Predolac <spredolac@fb.com>
Date: Tue, 10 Jun 2025 11:44:23 -0700
Subject: [PATCH] Add several USDT probes for hpa

---
 src/hpa_hooks.c | 13 +++++++++++--
 src/hpdata.c    |  5 +++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/hpa_hooks.c b/src/hpa_hooks.c
index 45bebe41..14005ae0 100644
--- a/src/hpa_hooks.c
+++ b/src/hpa_hooks.c
@@ -2,6 +2,7 @@
 #include "jemalloc/internal/jemalloc_internal_includes.h"
 
 #include "jemalloc/internal/hpa_hooks.h"
+#include "jemalloc/internal/jemalloc_probe.h"
 
 static void    *hpa_hooks_map(size_t size);
 static void     hpa_hooks_unmap(void *ptr, size_t size);
@@ -19,16 +20,20 @@ const hpa_hooks_t hpa_hooks_default = {&hpa_hooks_map, &hpa_hooks_unmap,
 static void *
 hpa_hooks_map(size_t size) {
 	bool commit = true;
-	return pages_map(NULL, size, HUGEPAGE, &commit);
+	void *ret = pages_map(NULL, size, HUGEPAGE, &commit);
+	JE_USDT(hpa_map, 2, size, ret);
+	return ret;
 }
 
 static void
 hpa_hooks_unmap(void *ptr, size_t size) {
+	JE_USDT(hpa_unmap, 2, size, ptr);
 	pages_unmap(ptr, size);
 }
 
 static void
 hpa_hooks_purge(void *ptr, size_t size) {
+	JE_USDT(hpa_purge, 2, size, ptr);
 	pages_purge_forced(ptr, size);
 }
 
@@ -52,12 +57,14 @@ hpa_hooks_hugify(void *ptr, size_t size, bool sync) {
 	if (sync) {
 		err = pages_collapse(ptr, size);
 	}
+	JE_USDT(hpa_hugify, 4, size, ptr, err, sync);
 	return err;
 }
 
 static void
 hpa_hooks_dehugify(void *ptr, size_t size) {
 	bool err = pages_nohuge(ptr, size);
+	JE_USDT(hpa_dehugify, 3, size, ptr, err);
 	(void)err;
 }
 
@@ -78,7 +85,9 @@ hpa_hooks_ms_since(nstime_t *past_nstime) {
 static bool
 hpa_hooks_vectorized_purge(void *vec, size_t vlen, size_t nbytes) {
 #ifdef JEMALLOC_HAVE_PROCESS_MADVISE
-	return pages_purge_process_madvise(vec, vlen, nbytes);
+	bool err = pages_purge_process_madvise(vec, vlen, nbytes);
+	JE_USDT(hpa_vectorized_purge, 3, nbytes, vlen, err);
+	return err;
 #else
 	return true;
 #endif
diff --git a/src/hpdata.c b/src/hpdata.c
index 9d324952..e9ee2738 100644
--- a/src/hpdata.c
+++ b/src/hpdata.c
@@ -2,6 +2,7 @@
 #include "jemalloc/internal/jemalloc_internal_includes.h"
 
 #include "jemalloc/internal/hpdata.h"
+#include "jemalloc/internal/jemalloc_probe.h"
 
 static int
 hpdata_age_comp(const hpdata_t *a, const hpdata_t *b) {
@@ -100,6 +101,8 @@ hpdata_reserve_alloc(hpdata_t *hpdata, size_t sz) {
 	    hpdata->touched_pages, HUGEPAGE_PAGES, result, npages);
 	fb_set_range(hpdata->touched_pages, HUGEPAGE_PAGES, result, npages);
 	hpdata->h_ntouched += new_dirty;
+	JE_USDT(hpa_reserve, 5, npages, hpdata->h_nactive, hpdata->h_ntouched,
+	    new_dirty, largest_unchosen_range);
 
 	/*
 	 * If we allocated out of a range that was the longest in the hpdata, it
@@ -160,6 +163,8 @@ hpdata_unreserve(hpdata_t *hpdata, void *addr, size_t sz) {
 	hpdata->h_nactive -= npages;
 
 	hpdata_assert_consistent(hpdata);
+	JE_USDT(hpa_unreserve, 5, npages, hpdata->h_nactive, hpdata->h_ntouched,
+	    old_longest_range, new_range_len);
 }
 
 size_t